Infants under 6 months of age are at increased risk of both influenza (flu) and pertussis disease, and pregnant women risk serious illness and premature labor from flu. The Advisory Committee on Immunization Practices recommends that women receive a flu vaccine in flu season, and tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) vaccine during each pregnancy (ideally between 27-36 weeks) to lower the risk for flu and pertussis disease for themselves and their infants. However, only half of pregnant women in the US receive a flu and Tdap vaccine, respectively; only 33% of women receive both vaccines. Lack of vaccination stems from a combination of patient (lack of knowledge, vaccine hesitancy), provider (suboptimal communication skills, missed opportunities), and system (e.g. lack of standing orders and patient reminders) factors. An effective intervention is needed to improve flu and Tdap vaccination rates for pregnant women. We will adapt our highly successful QI-based interventions (communication training, provider prompts, provider feedback, and standing orders) and reminder/recall interventions used for other vaccines to the VAX-MOM project. Aim 1 of this project is to measure baseline flu/Tdap vaccination coverage and provider knowledge, attitudes and behaviors for flu/Tdap vaccination in 32 OB/GYN practices in 4 health systems in NY and CA. Aim 2 is to use a clustered RCT (practice randomization) to measure the effect of a multi-component QI intervention (VAX-MOM: training in communication, provider prompts, standing orders + feedback on rates) on vaccination rates and provider attitudes, and to measure costs of the intervention. Aim 3 is to measure the effect of a patient-based reminder/education intervention on vaccination rates of pregnant mothers, using a RCT provided to control practices (with patient randomization) in Year 3. Aim 4 is to develop a translation plan/toolkit for OB/GYN practices and health systems for maternal vaccination. If the VAX-MOM intervention and the patient reminder/education studies are successful, we will have a scalable set of interventions at both the practice level and the health system level to raise maternal vaccination rates.